1. Field of the Invention
The present invention relates to an articulated strap with links which are arranged so as to penetrate one into the other in the longitudinal direction and are connected by means of transverse hinge pins.
2. Description of the Related Art
Straps of this type are known, in particular watch straps, in which at least some transverse series of adjacent links are demountable in order to make it possible to alter the length of the strap as a function of the size of the wrist of the wearer of this strap. In general, these demountable transverse series of links are assembled by means of screws which are visible on the edge of the strap. The other transverse series of links are connected by means of studs driven into the lateral links, in order to allow these to pivot with respect to the central links.
Apart from the fact that the screws are visible, such a strap is not fully demountable and requires delicate action to separate the links held by studs, should it become necessary to change a link.
EP-0089 421, WO 93/08713 and WO 94/12069 have already proposed demountable articulated straps assembled by means of articulation elements engaged freely on pivot pins, these articulation elements being locked by means of members screwed to that side of the strap which faces the wearer's arm, so that the screws are not visible when the strap is worn. This is firmly an improvement in aesthetic terms, although it could not fulfill the most demanding criteria associated with articles which are top of the range. To be precise, in a showcase or at the time of purchase, the customer first sees the strap when it is not being worn, and he can therefore see the fastening screws, whatever the face of the strap on which they appear. Seeing the screws immediately gives such a strap the character of an article where the functional aspect has superseded the aesthetic aspect, and this obviously does not add to the value of a top-of-the range article of this type, the faultless appearance of which is a token of its good workmanship.
The patent CH-558 153 relates to an articulated strap comprising links integral with a transverse articulation rod which projects at one end of the link and does not extend over the entire width of the latter. This rod is introduced into a receptacle opening onto the lower face of the adjacent link and is held in place by a spring-type locking element. In this case, the screws are replaced by a spring. Where a strap made from gold is concerned, it will be difficult for such a spring to be produced from the same metal as the strap. Moreover, although there is no screw, this fastening member must have an orifice to allow demounting and therefore retains a functional and non-decorative character giving it an appearance whose aesthetic value is not in keeping with the rest of the strap.
Another solution has been proposed in CH-688 430, which involves forming links comprising three parts of different widths which are offset longitudinally in relation to one another. A narrow central part is followed by a part of intermediate width, extending on either side of the mid-axis of the strap, and finally by a part, the width of which corresponds to that of the strap. Each central part and each part of intermediate width is pierced transversely to the strap. Each wide part of the link comprises a clearance having a width corresponding to the intermediate width, and each intermediate part comprises a clearance having a width corresponding to the narrowest central part. Consequently, two adjacent links can fit one into the other and be retained together by means of a bar slipped into the coaxial transverse orifices of the intermediate parts and of the central part of the adjacent link. This bar passes freely through these orifices, but is retained axially as soon as the next link is put in place. To be precise, the bar comes into abutment against the edges of the clearance of corresponding width of this next link and is therefore blocked axially. The main disadvantage of this solution is that the amplitude of articulation of the links must be limited so as to ensure that the bar is always in abutment against the edges of the clearance of the next link. Moreover, with this solution, the links are necessarily offset longitudinally in relation to one another.
Finally, EP 0 310 536 has proposed a strap comprising two rows of lateral links, each integral with a half-shaft which terminates in a head adjacent to a groove. Two intermediate links are arranged between these lateral links and a central link. The intermediate links have two parallel passages with transverse axes, one of which passages is intended for receiving a half-shaft, at the same time allowing the head and the adjacent groove to project. The central fastening link possesses a longitudinal recess, the cross section of which is of a shape complementary to that of the two heads of the two half-shafts. The longitudinal recess opens at one end and has two lateral slots, the width of which corresponds to the diameter of the grooves adjacent to the heads of the half-shafts.
To mount the strap, the two half-shafts are engaged into the respective passages of two intermediate links, and then the two heads of the half-shafts are introduced into the longitudinal recess from the open end of the latter. Each pair of intermediate lateral links is slid along longitudinally until the other passages of the intermediate links coincide with the passage of the central link. A pivot rod is then introduced through the two passages, in such a way that all the links forming the strap are articulated about two axes.
Although such a strap does not comprise any screws and no element forming part of the assembly is visible in the position of use, that is to say when the strap surrounds the wrist, that end of the longitudinal recess which issues onto a lateral face of the strap becomes visible as soon as a sufficient angle is formed between this lateral face and the link adjacent to this lateral face.